Fluid mixer reactor

ABSTRACT

An improved fluid mixing device comprised of a plurality of stacked, relatively thin plates having fluid passage means therein to allow two or more fluids to pass therethrough and to be mixed with each other yet at least one of the fluids, in the form of a liquid, can be atomized to enhance the mixing action between the two fluids. The device is constructed so that one or both fluids can be used to cool the face plate of the device such as when the latter is adjacent to a combustion chamber. Various embodiments of the device are disclosed.

United States Patent [1 1 Schoenman et al.

[451 May 6,1975

[ FLUID MIXER REACTOR [7 51 Inventors: Leonard Schoenman, CitrusHeights;

Robert C. Schindler, Fair Oaks,

[21] Appl. No.: 398,031

[52] US. Cl 259/4; 23/252 [51] Int. Cl. B011 5/02; B01f 5/18 [58] Fieldof Search 259/4, 18, DIG. 30, 36, 259/60; 138/38; 48/180 R, 180 H, 180B; 23/252 R [56] References Cited UNITED STATES PATENTS 3,206,170 9/1965Schippers 259/4 3,325,150 6/1967 Broders 259/4 11/1973 Schmitt.... 259/43,770,249 4/1974 Clasen 25 9/4 Primary ExaminerRobert W. JenkinsAttorney, Agent, or Firm-John L. McGannon; J. Georg Seka; John S. Bell[5 7 ABSTRACT An improved fluid mixing device comprised of a pluralityof stacked, relatively thin plates having fluid pas sage means thereinto allow two or more fluids to pass therethrough and to be mixed witheach other yet at least one of the fluids, in the form of a liquid, canbe atomized to enhance the mixing action between the two fluids. Thedevice is constructed so that one or both fluids can be used to cool theface plate of the device such as when the latter is adjacent to acombustion chamber. Various embodiments of the device are disclosed.

15 Claims, 7 Drawing Figures PATENTEB W5 3.881.701

SHEET 18! 3 FIG. 2

PATENTED 51975 3.881 .701

SHEET 2 UP 3 FIG. 4

PATENTEDIEAY 61975 3, 1,701

SHEET 3 GF 3 FIG. 5

FIG. 6

FLUID MIXER RIC/\("IOR This invention relates to improvements in themixing of two different fluids prior to utilization of the mixture and,more particularly. to an improved fluid mixing device adapted to mix andatomize fluids as well as to utilize one of a number of fluids forcooling of the device itself.

The present invention is directed to a self-cooled device which achievesthe efficient atomization and mix ing of two or more either inert orreactive fluids. lt accomplishes liquid stream atomization and/or vaporphase mixing by hydraulic or mechanical means or a combination of both.Mixing of two different fluids can be concurrent with the atomizationprocess or can follow atomization. The mixer device can operate using aplurality of fluids and can be designed to stage the mixing processesthrough controlled variation in mass and mixture ratio and primary andsecondary mixing and/or reaction.

The fluid mixer device of this invention is comprised of a plurality ofthin plates which contain fluid-flow passages or channels. Dependingupon the composition of the fluids and the platelet material, the platescan be joined in any one of a number of different ways, such as bydiffusion bonding, a brazing, or adhesive. Platelet flow passages can bearranged so that a selected fluid is routed to provide cooling of themixer wall.

The device provides efficient mixing control by dividing the total fluidflow into a very large number of precisely metered, very small streamswhich are atomized prior to or during their mixing with adjacentstreams. All control of liquid flow, and indirectly of liquidatomization. and mixing is by means of the laminate or channel shape anddepth. The fluid discharge from the device is through apertures whichare normal to an end plate of the device, resulting in the outer face ofthe end plate being a continuous member and the platelet bond lines notbeing exposed to the reaction which follows mixing.

The quantity of outlets on the outer face of the device can be up toseveral hundred per square inch, with each discharging a stream offinely atomized fluid. Var iation in the design of the device allowsthese streams to consist of singular fluids or mixtures resulting fromimpingement of unlike streams. These sprays of atomized fluid can bedirected to impinge on each other to acheive a controlled primary mixingzone exteriorly or interiorly of the device or, if directed axially,will experience secondary mixing by virtue of their proximity.

The advantage of this device over other microelement platelet-typemixers is that the following can be achieved without an increase instream size or flow per element:

(l) Fewer plates are needed, resulting in reduced structural complexityand fewer bonded interfaces (2) The outer face of the surface can be asingle, continuous member so that bond joints between the stacked platesof the device need not be exposed.

(3) Atomization can be accomplished by stream impingement against anintegral splash plate, like-onlike stream impingement, or like-on-unlikestream impingement. Since droplet size is not totally dependent uponorifice size, larger, less easily plugged passages and orifices can beutilized.

(4). Mixing is achieved by directed impingement or unlike spraysfollowing their atomization.

(5). The outer face of the device can be flat or can have a simple orcompound curvature. The face boundary can be polygonal or circular.

The invention, in providing a means of atomizing and mixing reactive ornonreactive fluids proximate to the surface of a flat or curved plate,is suitable for use in the following applications but is not limitedthereto:

l. Propellant injection on both liquid and gaseous propellant rocketengines.

2. Fluid injection to provide jet interaction for maneuverable reentrybodies.

3. Liquid propellant injection for very low thrust liquid propellantrocket engines.

4. Gas turbine propellant injection.

5. Chemical process mixing with both reactive and inert fluids.

6. Gas-liquid mixing for internal combustion engines,

7. Exhaust reactors.

8Chemical laser devices.

The primary object of this invention is to provide an improved fluidmixer device of the type comprised of a plurality of stacked, relativelythin plates arranged with certain fluid passages therein so that thestack of plates can provide a fluid manifold and distribution system, acoolant, system, and an atomizing and'mixing system tailored toaccommodate two or more different fluids, such as a fuel and atomizingagent, in an efflcent manner. 1

Another object of this invention is to provide a device of the typedescribed wherein the mixing of two different fluids can occurinteriorly or exteriorly of the device during or after atomization toprovide flexibility in the use of the device yet the device is highlyefficient irrespective of its particular use.

A further object of this invention is to provide a fluid mixing deviceof the aforesaid character wherein the device has a working end faceadapted to be placed near a reaction zone at which heat is generated,the device having fluid passage means for directing a fluid in proximityto the working face so that the fluid will be in heat exchangerelationship to such face and maintain the same in a relatively coolcondition to thereby minimize erosion of the face due to thedeteriorating effects of the heat generated thereto. Other objects ofthis invention will become apparentas the following specificationprogresses, reference being had to the accompanying drawings for severalembodiments of the invention:

In the drawings:

FIG. 1 is a fragmentary, perspective view of a fluid mixing device ofthis invention, showing the fluid passages therein and the working endface thereof, arrows indicating the directions of flow of fluidstherethrough;

FIG. 2 is a cross-sectional view of the device of FIG. 1;

FIG. 2a is an enlarged, fragmentary, perspective view of the embodimentof FIGS. 1 and 2, showing the way in which two fluid stream impinge uponeach other exteriorly of the device;

FIG. 3 is a view similar to FIG. 2 but showing another embodiment of thedevice; and

FIGS. 4, 5 and 6 are additional embodiments of the device with each ofthe latter embodiments utilizing a swirl chamber for generating a fluidstream in the form of a vortex to enhance mixing of fluids. A firstembodiment of the fluid mixing device of this invention is broadlydenoted by the numeral I0 and is illustrated in FIGS. 1 and 2. Device isformed of a plurality of stacked plates 12, 14, 16, 18, 20, 22 and 24,which are all of the same shape. For purposes of illustration, each suchplate is rectangular but could have other shapes as well. Plates 12 -24may be of any suitable material, such as metal. The plates are bonded toeach other in any suitable manner, such as by diffusion bonding, bybrazing or by use of an adhesive. Plate 12 comprises the outer end plateof the device and is adapted to be placed adjacent to the region atwhich fluids emanating from device 10 are further utlilized, such as acombustion chamber of a rocket engine.

The various plates of device 10 are relatively thin and, while they areshown as being of the same thickness, they could vary in thickness fromeach other to suit specific requirements. A typical range of thicknessesfor such plates is 0.002 inch to 0.030 inch. Since the plates are sothin, fluid channels or passages formed therein are preferably formed bya conventional photoetching technique to achieve the relatively finedimensions of the passages. Typical dimensions of such passages are ofthe order of magnitude of the plate thicknesses.

Device 10 operates in a threefold manner, namely, it defines a fluidmanifold and distribution system; it defines a coolant system whereinheat input from the region adjacent to end plate 12 is conducted to oneor several of the fluids passing through the device; and it serves as anatomization and mixing system tailored to accommodate selected fluids.

As shown in FIG. 1, plate 12 has a plurality of pairs of openings 26 and28, each pair of openings being adjacent to each other and arranged sothat the fluid streams issuing therefrom will be in the form of spraysdirected toward each other in the manner shown in FIG. 1. Plate 12 has aplurality of such pairs of openings 26 and 28. Typically, there areabout 10 to 100 or so pairs of openings 26 and 28 per square inch ofplate 12. For purposes of illustration, each opening is trapezoidal inshape with the longer sides of the openings being adjacent to each otherso that the sides of one opening diverge as the other opening isapproached as shown in FIG. 1.

Plate 14 immediately adjacent to plate 12 has a number of fluid channels30 (FIG. 1) for delivering a fluid, such as a liquid, from one side ofdevice 10 across the device and along and in heat exchange relationshipto the inner surface of plate 12. In the downstream end of each channel30, plate 16 has a circular hole 32 placing the corresponding channel 30in fluid communication with a fluid passage 34 in plate 18 transverse tochannel 30.'Thus, fluid passing from channel 30 into opening 32 andthrough passage 34 can flow into a second opening 36 in plate 16, thenup through an opening 38 in plate 14 and out of device 10 through acorresponding opening 26. Serpentive arrow 39 (FIG. 2) illustrates thepath of flow of fluid from a channel 30 to the corresponding opening 26.Opening 38 in plate 14 is larger in size than opening 36 of plate 16 asshown in FIG. 2. Also, opening 26 is partially aligned with opening 38so that a portion 40 of plate 12 overhangs opening 38 to present a lipor projection causing a fluid stream passing from holes 36 and 38 tobent laterally as shown in FIG. 2. Furthermore, portion 40causesatomization of the fluid passing the same before the fluid exitsfrom device 10. The fluid exits from opening 26 along an inclined pathas shown in FIG. 1, 2 and 3.

A second fluid directed toward each opening 28 flows upwardly throughaligned holes 44, 46, 48, 50v

and 52 in plates 24, 22, 20, 18 and 16, respectively. Plate 14 has anenlarged hole 54 in fluid communication with holes 52 and thecorresponding opening 28 partially overlies on end of opening 54 todefine an over-hanging or projecting portion 56 which serves the samepurpose as portion 40, namely to atomize the fluid before it exits fromdevice 10. The fluid leaving each opening 28 is directed along aninclined path extending toward the fluid path extending away from thecorresponding opening 26. Serpentive arrow 57 (FIG. 2) represents theflow of the second fluid through device 10 toward a correspondingopening 28. While the second fluid is shown in FIG. 2 as coming from achan-v nel 59 remote from end plate 12, it is possible to form plate 14so that the second fluid can be moved into heat exchange relationship toplate 12 so that both fluids operate to cool such plate.

The sprays issuing from each pair of opening 26 and 28 are denoted byarrows 58 and 60 (FIG. 2a). The two sprays, both of which have beenpreviously atomized, mix together at a zone 62 substantially midwaybetween each pair of openings 26 and 28. After mixing together, themixture is ready for use, such as the fueloxidizer source for acombustion chamber. Thus, device 10 allows atomization of at least oneof the fluids within the device, whereas, mixture of the two fluidsoccurs exteriorly of the device. Device 10 is adapted for use whendirect impingement of liquids to be mixed within device 10 is notdesired, i.e., when an exothermic reaction occurs upon impingement.Variations in the shapes of the holes in plates 12 and 14 and thespacing of openings 26 and 28 allow the spray character (spray shape anddroplet size) -as well as the position of impingement zone 62 to bevaried.

The second embodiment of the fluid mixer device of this invention isshown in FIG. 3 and is denoted by the numeral 110. Device includes astack of plates 112, 114, 116, 118, 120, 122 and 124, such stack beingarranged to operate in a manner to cause a direct impinging mixingaction of two fluid streams within the device itself to causeatomization. Also, mixing of two different fluids occurs within thedevice.

A first fluid enters device 110 along a pair of paths denoted by arrows126 and 128 and passes through respective holes 130 and 132 in plates124 and 122, respectively. I-Ioles 132 communicate with respective fluidpassages 134 in plate 120, passages 134 being opposed to each other andterminating at a central opening 136 aligned with a shaped slot 138 inplate 118 and with shaped slots 140, 142 and 144 in plates 116, 114 and112, respectively. Slots 140, 142 are of greater size than slot 138.Thus, within opening 136, the two streams of the first fluid flowingalong the path denoted by arrows 126 and 128 impinge upon each other tocause atomization of the first fluid. The resulting mixture is expelledthrough shaped slot 138 in plate 118.

Plate 116 has opposed fluid passages 146 formed therein whichcommunicate with transverse passages 148 in plate 114. A second fluidentering passages 148 flows through the same to cool end plate 112. Thefluid then flows through respective, opposed passages 146 in plate 116along paths denoted by arrows 150 and 152. The two fluid streams exitfrom passages 146 and impinge against each other at the center of slotto cause atomization of the second fluid. Plate 1 14 can be constructedso that passages 148 can be fed from the edge of device 110 or bypassages from one extremity thereof which penetrate through plates116-124.

There is a mixing action within shaped slots 140, 142 and 144 of the twodifferent fluids, namely, the first fluid entering device 1 along paths126 and 128 and the second fluid entering along paths 150 and 152. Themixture occurs prior to exit from device 110. Before such mixing action,the first fluid will have been atomized by impingement of the twostreams thereof within opening 136.

FIG. 4 illustrates a third emobidment of the device of this inventionwherein mixing of two fluids is accomplished by a vortex action. Thedevice of this embodiment, denoted by the numeral 210, is comprised ofplates 212, 214, 216, 218, 220, 222 and 224 arranged in a stack. Asbefore, plate 212 will have a number of shaped slots or openings 226 persquare inch. The vortex action occurs within device 210 when a firstfluid, flowing along a path denoted by arrow 228, passes through atangential port 230 at the inner end of a fluid passage 236 in plate 220and enters a swirl chamber 232 also in plate 220. Plate 218 has a shapedslot 234 communicating with and defining the outlet of the swirlchamber. The fluid entering the swirl chamber initially reaches fluidpassage 236 by way of openings 238 and 240 in plates 222 and 224,respectively. Opening 240 is in fluid communication with a manifold 241adapted to be coupled to a source of the first fluid.

Plate 216 contains a shaped slot 252 and a pair of fluid passages 242and 244 which communicate with transverse passages 246 in plate 214. Asecond fluid flowing through passages 246 toward passages 242 and 244will cool plate 212. The second fluid flows through passages 242 and 244along paths denoted by arrows 248 and 250 and enters the vortex createdby the first fluid because passages 242 and 244 are on opposite sides ofthe vortex. The two fluids are thus mixed together within device 10 andflow out of the same in vortex fashion through shaped slots 252,254 and266 in plates 216, 214 and 212, respectively. Fluid can be fed topassages 246 in plate 214 from the edge of the stack or from a locationthereon by means of passages through plates 216-224. While the vortexaction within device 10 serves to mix the two different fluids with eachother, it also serves to atomize the second fluid.

FIG. 5 illustrates still another embodiment of a fluid mixer deviceutilizing an internally generated vortex. In FIG. 5, the fluid mixerdevice 310 is comprised of stacked plates 312, 314, 316, 318, 320, 322and 324. A swirl chamber 326 is provided in plate 320 and has an outletdenoted by a shaped slot 328 in plate 318. A first fluid is suppliedalong a path 330 to the swirl chamber plate 320 after the fluid haspassed through openings 332 and 334 in plate 324 and 322, respectively,and through a fluid passage 336 also in plate 320. Passage 336 has anexit port 338 which is tangential to swirl chamber 326 to create thevortex indicated by the spiral arrow 340 leaving device 310 throughshaped openings 342, 343 and 345 in plates 312, 314 and 316,respectively. As before, face plate 312 has a plurality of openings 342per unit area inasmuch as the relative sizes of the various openings andpassages in each plate are quite small.

A second fluid is fed through transverse passage 344 in plate 314, therebeing a pair of passages 344 on each side of the vortex, respectively.Passages 344 serve to permit the second fluid to cool end plate 312before mixing with the first fluid in the vortex. The two streams of thesecond fluid which leaves each pair of passages 344 enters a passage 346whereby impingement of the two streams causes atomization of the secondfluid before passing through shaped slot 348 which causes the atomizedsecond fluid to leave device 310 in the form of a spray. Then the secondfluid streams denoted by arrows 349 are directed toward and intersectthe vortex of the first fluid to create a mixing action between the twofluids.

FIG. 6 illustrates a modification of the embodiment of FIG. 5 in thatplate 314 is provided with only a single passage instead of a pair ofsuch passages on each side of the vortex, respectively. The singlepassage, denoted by the numeral 344a communicates with a passage 346athe latter being in fluid communication with slot 348a to causeatomization of the fluid flowing along a path denoted by the numeral350a. Atomization occurs because of the. overhanging portion 3520 ofplate 312 with respect to passage 346a The second fluid then flows alongan inclined path as it leaves device 310 through each slot 348a andintersects the vortex of the first fluid whereby the two fluids aremixed together. As before, the second fluid passing through passages344a cools end plate 312.

We claim:

1. A fluid mixing device comprising: a plurality of relatively thinplates arranged in a stack to form a platelet assembly, one of theplates being at the end of the stack and provided with an outletopening, the plate next, adjacent to said end plate having an elongatedchannel for receiving a first fluid and for placing the latter in heatexchange relationship to the end plate, said assembly having firstpassage means coupled with the channel for directing the first fluidfrom the latter to said opening, a second passage means for directinga-secondfluid into mixing relationship to the first fluid,-and meansdefined by said passage means and employing the kinetic energy of theflowing fluid for atomizing at least one of the fluids as it flowsthrough said assembly and prior to its being mixed with the other fluid.

2. A device as set forth in claim 1, wherein said end plate has a secondopening adjacent to said first opening, the second passage meanscommunicating with the second opening, said first passage means and saidsecond passage means defining respective first and second passagesoriented to cause the first and second fluids leaving the assemblythrough the openings to traverse inclined paths converging toward eachother as the flu- I ids flow away from said end plate, whereby thefluids are mixed together exteriorly of said assembly.

3. A device as set forth in claim 1, wherein said atomizing meanscomprises a lip extending partially across the path of said one fluidfor engaging the same and for reducing the particle size thereof as thefluid flows past the lip.

4. A device as set forth in claim 1, wherein the end plate has aplurality of pairs of shaped outlet slots, there being a first passagemeans and a second passage means for each pair of slots, respectively,one of the slots of each pair communicating with the corresponding firstpassage means and the other slot of each pair communicating with thecorresponding second passage means, the slots of each pair beingarranged to present a fluid spray therefrom with the sprays beingdirected toward each other for mixture at a zone exteriorly of the stackand between said pair of slots.

5. A device as set forth in claim 1, wherein a first of said plates ofsaid assembly has a pair of opposed fluid passage therein communicatingwith said outlet opening, and wherein the atomizing means comprisesmeans for directing one of the fluids through said opposed fluidpassages and toward and into impinging relationship to each other tocause atomization ofsaid one fluid prior to flow thereof out of saidassembly through said outlet opening.

6. A device as set forth in claim 1, wherein each of a pair of saidplates has a pair of opposed fluid passages therein communicating withsaid outlet opening. and wherein the atomizing means comprises meanscoupled with each pair of fluid passages, respectively. for directing arespective fluid thereto whereby the fluid will pass therethrough in apair of streams and the streams will impinge upon each other and atomizethe fluid before the fluid passes out of the assembly through saidoutlet opening.

7. A device as set forth in claim 6, wherein the zone of impingement ofthe first fluid is disposed between the outlet opening and the zone ofimpingement of the second fluid.

8. A device as set forth in claim 1, wherein said atomizing means isdefined by a swirl chamber.

9. A device as set forth in claim 1, wherein one of the plates has meansdefining a swirl chamber. the latter forming a part of said secondpassage means. whereby the second fluid entering the swirl chamber willbe caused to form a vortex which advances toward. through and out ofsaid outlet opening. said first passage means including an outlet slotadjacent to said outlet opening and disposed to permit said first fluidto leave said assembly and to travel toward and into intersectingrelationship to the vortex at a location exteriorly of said assembly.

10. A device as set forth in claim 9, wherein said atomizing meansincludes means defined by said plate adjacent to said end plate fordividing the first fluid into two streams and for directing the twostreams into impingement with each other upstream of said outlet slot toeffect atomization of the first fluid. said dividing and directing meansbeing disposed to permit the first fluid to leave the assembly throughsaid outlet port along a path substantially perpendicular to said endplate.

11. A device as set forth in claim 9, wherin said plate adjacent to saidend plate includes a fluid passage defining said first passage means.said fluid passage being oriented in partial underlying relationship tosaid end plate and in partial fluid communication with said outlet slotto cause the first fluid to pass out of the assembly through said outletslot along an inclined path extending toward the path of the vortex.

12. A device as set forth in claim 11, wherein said atomizing meanspresents a projection defined by said end plate at one side of saidoutlet slot in the inclined path of said first fluid to causeatomization hereof.

13. A fluid mixing and atomizing device for forming an atomized mixtureof at least two fluids and for directing the fluids into a surroundingatmosphere comprising a plurality of relatively thin plates arranged ina stack to form a platelet assembly. a front of the assembly beingdefined by an end plate having at least one outlet opening. first fluidpassage means for flowing a first fluid through the stack and to theoutlet opening. second fluid passage means for flowing a second fluidthrough the stack into mixing relationship with the first fluid. andmeans for atomizing at least one of the fluids before its discharge fromthe stack and before being mixed with the other fluid. the atomizingmeans comprising means defined by at least one of the passage means forguiding the fluid flow through such passage means so that such fluid isatomized by virtue of its flow through the passage means.

14. A device according to claim 14 wherein the atomizing means includesmeans for impinging two fluid streams flowing in the stack.

15. A device according to claim 14 wherein the atomizing includes meansfor causing at least one fluid stream in the stack to abruptly changeits flow direction to thereby atomize the fluid such streams.

1. A fluid mixing device comprising: a plurality of relatively tHinplates arranged in a stack to form a platelet assembly, one of theplates being at the end of the stack and provided with an outletopening, the plate next adjacent to said end plate having an elongatedchannel for receiving a first fluid and for placing the latter in heatexchange relationship to the end plate, said assembly having firstpassage means coupled with the channel for directing the first fluidfrom the latter to said opening, a second passage means for directing asecond fluid into mixing relationship to the first fluid, and meansdefined by said passage means and employing the kinetic energy of theflowing fluid for atomizing at least one of the fluids as it flowsthrough said assembly and prior to its being mixed with the other fluid.2. A device as set forth in claim 1, wherein said end plate has a secondopening adjacent to said first opening, the second passage meanscommunicating with the second opening, said first passage means and saidsecond passage means defining respective first and second passagesoriented to cause the first and second fluids leaving the assemblythrough the openings to traverse inclined paths converging toward eachother as the fluids flow away from said end plate, whereby the fluidsare mixed together exteriorly of said assembly.
 3. A device as set forthin claim 1, wherein said atomizing means comprises a lip extendingpartially across the path of said one fluid for engaging the same andfor reducing the particle size thereof as the fluid flows past the lip.4. A device as set forth in claim 1, wherein the end plate has aplurality of pairs of shaped outlet slots, there being a first passagemeans and a second passage means for each pair of slots, respectively,one of the slots of each pair communicating with the corresponding firstpassage means and the other slot of each pair communicating with thecorresponding second passage means, the slots of each pair beingarranged to present a fluid spray therefrom with the sprays beingdirected toward each other for mixture at a zone exteriorly of the stackand between said pair of slots.
 5. A device as set forth in claim 1,wherein a first of said plates of said assembly has a pair of opposedfluid passage therein communicating with said outlet opening, andwherein the atomizing means comprises means for directing one of thefluids through said opposed fluid passages and toward and into impingingrelationship to each other to cause atomization of said one fluid priorto flow thereof out of said assembly through said outlet opening.
 6. Adevice as set forth in claim 1, wherein each of a pair of said plateshas a pair of opposed fluid passages therein communicating with saidoutlet opening, and wherein the atomizing means comprises means coupledwith each pair of fluid passages, respectively, for directing arespective fluid thereto whereby the fluid will pass therethrough in apair of streams and the streams will impinge upon each other and atomizethe fluid before the fluid passes out of the assembly through saidoutlet opening.
 7. A device as set forth in claim 6, wherein the zone ofimpingement of the first fluid is disposed between the outlet openingand the zone of impingement of the second fluid.
 8. A device as setforth in claim 1, wherein said atomizing means is defined by a swirlchamber.
 9. A device as set forth in claim 1, wherein one of the plateshas means defining a swirl chamber, the latter forming a part of saidsecond passage means, whereby the second fluid entering the swirlchamber will be caused to form a vortex which advances toward, throughand out of said outlet opening, said first passage means including anoutlet slot adjacent to said outlet opening and disposed to permit saidfirst fluid to leave said assembly and to travel toward and intointersecting relationship to the vortex at a location exteriorly of saidassembly.
 10. A device as set forth in claim 9, wherein said atomizingmeans includes Means defined by said plate adjacent to said end platefor dividing the first fluid into two streams and for directing the twostreams into impingement with each other upstream of said outlet slot toeffect atomization of the first fluid, said dividing and directing meansbeing disposed to permit the first fluid to leave the assembly throughsaid outlet port along a path substantially perpendicular to said endplate.
 11. A device as set forth in claim 9, wherin said plate adjacentto said end plate includes a fluid passage defining said first passagemeans, said fluid passage being oriented in partial underlyingrelationship to said end plate and in partial fluid communication withsaid outlet slot to cause the first fluid to pass out of the assemblythrough said outlet slot along an inclined path extending toward thepath of the vortex.
 12. A device as set forth in claim 11, wherein saidatomizing means presents a projection defined by said end plate at oneside of said outlet slot in the inclined path of said first fluid tocause atomization hereof.
 13. A fluid mixing and atomizing device forforming an atomized mixture of at least two fluids and for directing thefluids into a surrounding atmosphere comprising a plurality ofrelatively thin plates arranged in a stack to form a platelet assembly,a front of the assembly being defined by an end plate having at leastone outlet opening, first fluid passage means for flowing a first fluidthrough the stack and to the outlet opening, second fluid passage meansfor flowing a second fluid through the stack into mixing relationshipwith the first fluid, and means for atomizing at least one of the fluidsbefore its discharge from the stack and before being mixed with theother fluid, the atomizing means comprising means defined by at leastone of the passage means for guiding the fluid flow through such passagemeans so that such fluid is atomized by virtue of its flow through thepassage means.
 14. A device according to claim 14 wherein the atomizingmeans includes means for impinging two fluid streams flowing in thestack.
 15. A device according to claim 14 wherein the atomizing includesmeans for causing at least one fluid stream in the stack to abruptlychange its flow direction to thereby atomize the fluid such streams.